That increase would come on top of a 46 percent increase in the property tax rate and a 3.3 percent increase in ambulance fees that was put in place this year to fund the EMS system.

LaSala said the hike is necessary to maintain the status quo but warned commissioners that the county is rapidly nearing a crisis point when the quality of service could decline. He called the situation an "inadvertent perfect storm" caused by increasing costs and limited revenues. Time, he said, is running out for the commission to change the system while keeping the current level of service.

"We need to find a way to reduce costs while maintaining the level of service," LaSala said.

His proposal would take the EMS property tax rate from about 85 cents per $1,000 of assessed, taxable value to about $1.04 — a 21.7 percent jump.

EMS taxes on a $150,000 home with a $50,000 homestead exemption is about $85 currently. Under the new rate, the EMS property taxes would be about $104.

Property taxes make up about 40 percent of the current $103.4 million budget. The rest comes from ambulance fees and other sources. LaSala is projecting that the 2012-13 EMS budget will be roughly $113.2 million.

It's unclear whether commissioners will agree to the tax hike.

The commission must unanimously agree to the change and, last year, most were firm in saying they would not raise the property tax rate again to fund EMS.

"I intend to stand firm," Commissioner Norm Roche said. "I did not approve an increase last year and I do not intend to approve an increase this year."

The alternative is to raid the $16.5 million savings in the EMS fund.

LaSala has advised against such a raid, saying it could put the county in a vulnerable spot in the event of a disaster, such as a hurricane. Instead, LaSala wants to put more into the savings account, increasing it by about $6.1 million to about $22.6 million.

Commissioners are scheduled to discuss all the county budgets, including EMS, during a workshop next Tuesday. They are scheduled to give tentative approval to the budgets on Sept. 6 and final approval on Sept. 18. The new fiscal year begins Oct. 1.

Pinellas' EMS system has become an emotional battleground over the past few years as property values have dropped and expenses have gone up.

LaSala last year proposed changing the way the county pays the 18 fire departments that provide Pinellas EMS service. He wanted to limit pay for firefighter/paramedics, cut the number of firefighters and reduce the number of emergency vehicles funded by the county.

LaSala's plan sparked outrage from fire officials, cities and fire districts who said it would adversely affect the level of service. Two alternate plans were submitted by firefighters. Both plans would have firefighters, rather than a private ambulance company, transport patients to the hospital.

The commission is scheduled to consider hiring a consultant at its July 24 meeting to evaluate both plans. But that study won't be back until next spring at the earliest. Then, LaSala said county officials will have to vet the report. Substantial change could take a year or two after that, he said.

That's a tight timeline for a commission that's pushing against the tax rate cap of $1.50 per $1,000 of assessed, taxable value. If the commission hits the cap and changes have not been made, serious issues would arise, LaSala said. "(That) can put us in a position where we're unable to maintain the current level of service because the funding isn't available to do so."

Anne Lindberg can be reached at alindberg@tampabay.com or (727) 893-8450.